This invention is related generally to overhead industrial light fixtures.
A wide variety of overhead industrial light fixtures exist to serve needs such as factory and warehouse illumination and the like, and a number of advances have been made over the years. However, existing overhead industrial light fixtures have a number of problems and shortcomings, and it is to addressing such problems and shortcomings that this invention is directed.
Of particular concern is that many overhead industrial light fixtures of the prior art are unwieldy in size and shape, which makes them expensive to manufacture, expensive to ship and store, difficult to install and service, in some cases unattractive in appearance and even unacceptable or difficult to use in certain size-restricted applications. In some cases an effort to make a more compact overhead industrial light fixture can tend to cause problems of overheating of critical components. While this might be addressed by use of baffles and other insulating features, such approaches increase manufacturing costs and comprises ease of installation and service.
One possible approach to deal with certain of the above problems and shortcomings is use of a housing with one or more external power-related components, such as the ballast. However, this approach complicates installation, increases cost and makes achieving a pleasing appearance difficult at best.
In the prior art, a variety of overhead industrial light fixtures are made using expensive die cast housings, and in some cases, complex housings with several parts are used to achieve various ends. In certain cases, complex sheet metal constructions have been used, but such constructions are complex, difficult to assembly and/or unwieldy in size and shape. In some cases, housings of the prior art do not lend themselves particularly well to easy assembly with power-related and other components. In some cases, various external parts are required in order to support the electrical components; such structures once again, do not lend themselves to a pleasing appearance in an overhead industrial light fixture.
This invention addresses such problems and shortcomings.
It is an object of this invention to provide, an improved overhead industrial light fixture overcoming some of the problems and shortcomings of the prior art.
Another object of the invention is to provide an improved overhead industrial light fixture which has a housing which is simple and inexpensive in structure and which facilitates assembly of the entire light fixture.
Another object of the invention is to provide an improved overhead industrial light fixture which includes a housing formed of only two pieces which can be fabricated of sheet metal.
Another object of the invention is to provide an improved overhead industrial light fixture which is simple in size and shape and therefore pleasing in appearance.
Another object of this invention is to provide an overhead industrial light fixture without any external power-related components or support structures.
Another object is to provide an improved overhead industrial light fixture that does not require an expensive die cast housing.
Still another object of the invention is to provide a low-profile overhead industrial light fixture which is compact and yet free of problems of overheating critical components.
Another object of this invention is to provide an overhead industrial light fixture which, although all power-related components are within a single housing, operates without excessive heat build-up.
Another object is to provide an improved overhead industrial light fixture that does not require internal baffles and/or insulation.
These and other objects of the invention will be apparent from the following descriptions and from the drawings.
This invention is an improvement in overhead industrial light fixtures of the type including a housing with top and bottom walls and sidewalls therebetween forming a substantially enclosed space, power-related components (e.g., a ballast, a capacitor and an ignitor), a lamp-mounting socket, and usually a reflector.
In the improvement of this invention, the housing has two enclosure-forming members consisting essentially of (1) a top member which forms the top wall and downwardly-extending sidewall portions; and (2) a bottom member which is shaped for fitted engagement with the top member and forms the bottom wall and upwardly-extending sidewall portions. The upwardly-extending sidewall portions of the bottom member and the downwardly-extending sidewall portions of the top member together complete the sidewalls of the housing.
It is most preferred that the downwardly-extending sidewall portions of the top member include two opposed endwalls, each extending downwardly from the top wall and terminating in an end flange which engages and is fastened to the bottom member. The end flanges of the endwalls are most preferably engaged with and fastened to the bottom wall.
In certain preferred embodiments of this invention, the top member includes (a) a central top-wall portion having opposite edges and (b) a pair of lateral top-wall portions below and on opposite sides of the central top-wall portion, each having an inner and an outer edge, and the downwardly-extending sidewall portions of the top member include a pair of opposed upper sidewall portions each extending downwardly from one of the opposite edges of the central top-wall portion to the inner edge of one of the lateral top-wall portions.
Most preferably, each of the lateral top-wall portions has a side flange at its outer edge, and such side flange and outer edge (of each lateral top-wall portion), at their common juncture, engage one of the upwardly-extending sidewall portions of the bottom member, to help provide the fitted engagement of the bottom member of the housing with the top member of the housing.
In certain preferred embodiments of this invention, the top and bottom members, with their aforementioned top or bottom surfaces, their side surfaces, and their flanges, are each formed of sheet metal which is bent to form the junctures referred to above between the top wall or the bottom wall and the sidewall portions of the top and bottom member, respectively.
In certain highly preferred embodiments, the housing bottom wall defines a socket window, and the socket is secured with respect to the housing such that it is positioned substantially within the enclosed space, with its lamp-receiving end substantially aligned, preferably both horizontally and vertically, with the socket window. This feature allows the light fixture to have a low profile, even with its components within a single housing.
In certain of such preferred embodiments, the bottom wall of the housing includes a plurality of downward projections around the socket window, and a reflector is secured to the housing by attachment thereto at the downward projections. Such projections allow the reflector to be mounted directly onto the housing in a manner providing an annular gap therebetween. This allows heat from the lamp to escape from the air within the reflector by convection through the annular gap.
It is most preferred in such embodiments that at least the bottom wall be formed of sheet metal and that the projections be stampings thereinxe2x80x94i.e., metal deformations made using normal metal-working press operations or the like.
As used herein, the following terms have the meanings given below, unless the context requires otherwise:
In referring to an overhead industrial light fixture, the term xe2x80x9coverheadxe2x80x9d refers to fixtures which are typically mounted, directly or indirectly, on ceilings or overhead structural members of some sort, such as in factories, warehouses, etc. (regardless of purpose), or any other overhead structure put in place for the purpose of supporting a light fixture. The term xe2x80x9cindustrialxe2x80x9d is used in order to differentiate from residential lighting or the like. Neither of these terms is to be taken as limiting.
The term xe2x80x9cpower-related componentsxe2x80x9d includes ballasts, capacitors, ignitors and other devices for creating the proper electrical power usable for a selected lamp, such as high-intensity discharge (HID) lamps of various kinds.
The term xe2x80x9csubstantially enclosed,xe2x80x9d as used with respect to a space within a housing, means surrounded, but does not mean closed from the inflow and outflow of air. Indeed, as can be seen in the drawings, certain of the walls of the housing are heavily vented to allow essentially unrestricted inflow and outflow of air, for purposes of cooling. This invention involves enclosure of power-related components and recessing of the socket into the housing, and for these reasons cooling by convection flow is of great importance.
As used with respect to the socket, the term xe2x80x9csubstantially withinxe2x80x9d does not rule out protrusion of a small portion of the lamp-receiving end of the socket from the housing, through the socket window.
The term xe2x80x9clow-profilexe2x80x9d as applied to a lighting fixture means that the fixture is lower in profile than occurs when the socket is not; recessed into the housing.
The terms xe2x80x9ctopxe2x80x9d and xe2x80x9cbottomxe2x80x9d used herein with reference to the fixture, or parts thereof, assume the normal use orientation of the fixture.
The overhead industrial light fixture of this invention, in its various forms, overcomes certain problems and shortcomings of the prior art, including those referred to above.